A fresh outbreak of Minamata Disease occurred in 1969, this time Niigata Prefecture. While the Chisso factory was not implicated, a factory owned by Showa Denko, using similar industrial processes to the Chisso plant, was found to be leaking mercury into the surrounding environment. Researchers familiar with the previous Minamata outbreak used their experience to prove Showa Denko's involvement in the new outbreak. By the time this new announcement was made, public sentiment was definitely changing in favour of the Minamata victims. Widespread publicity over the outbreaks as well as other pollution-related epidemics occurring during that same period meant that Minamata Disease sufferers were no longer regarded with the same stigma as before. The adverse health consequences of widespread release of industrial waste spurred a major campaign to reform Japanese environmental legislation. The two Minamata outbreaks, along with two other related cases, became known as the Four Big Pollution Diseases of Japan and spawned the environmental movement in Japan. The publicity also forced the Japanese government to launch its first Environmental Agency in 1971 (later expanded into a full Ministry of the Environment in 2001).
As for the victims of the two Minamata Disease outbreaks, the government released an official announcement on September 26, 1968 acknowledging that Minamata Disease was a condition of the central nervous system caused by methylmercury exposure. The announcement contained factual errors and completely omitted mention of the later victims who had become exposed when Chisso diverted its wastewater into the Shiranui Sea. Still, it represented vindication of a sort for the Minamata victims and their families and provided them with the means to force better financial compensation from the Chisso Corporation. As for Chisso itself, the dumping of methylmercury only stopped in 1968 when the old industrial equipment became outmoded and new technology became available.
When the Mutual Aid Society approached Chisso about a new compensation package however, the corporation in turn asked for a binding arbitration settlement from the Japanese government (as opposed to formal litigation). What followed was a government-run arbitration committee which initially offered to have Chisso pay 2 million yen for dead patients (approximately US $5,600) and 140,000 to 200,000 yen a year for surviving patients (US $390-560). Outraged over the proposed settlement, the victims' group representatives rejected the binding arbitration agreement and pushed for litigation. The political furour over the announced settlement was met with rioting and arrests of protesting victims.
In 1969, twenty-nine families of Minamata victims filed a lawsuit against Chisso and the media coverage of the trial gripped all of Japan. Graphic news footage of protesters being arrested and beaten, sit-ins outside Chisso's Tokyo offices, and officials from Chisso being confronted with one of the disabled children dominated headlines during the four years that it took for the trial to be completed. The most damaging testimony came from Hajme Hosokawa who told the court about his research which had been deliberately suppressed by Chisso's executives. Although Dr. Hosokawa died three months after giving his testimony, Chisso officials admitted that the dumping had continued despite the known risks.
The turmoil surrounding the Minamata trial also led to considerable social and political upheaval, especially since Chisso continued to be the largest employer in Minimata. When American photojournalist Eugene Smith began documenting Minamata Disease, he was brutally attacked by Chisso employees in an attempt to suppress his work. Although Smith survived the attack, the sight in one eye was left permanently damaged. Despite his injuries, Eugene Smith released this work on Minamata victims to critical acclaim. One of his most haunting pictures, Tomoko Uemura in her Bath, is considered to be Smith's greatest work although it has since been withdrawn from publication at the request of the victim's family.
In March of 1973, the Kumamoto District Court ruled in favour of the families. In handing down a verdict, the court ruled that the Chisso Corporation "could have prevented the occurrence of Minamata disease or at least have kept it at a minimum. We cannot find that the defendant took any of the precautionary measures called for in this situation whatsoever. The presumption that the defendant had been negligent from beginning to end in discharging wastewater from its acetaldehyde plant is amply supported. The defendant cannot escape liability for negligence." The original "sympathy money" agreement was scrapped and Chisso was ordered to pay 18 million yen for each deceased victim (US $66,000) and 16-18 million yen for each surviving victim (US $59,000-69,000). It was the largest settlement ever awarded by a Japanese court.
The actual number of Minamata Disease victims may never be known for certain. To receive compensation, disease victims needed to be officially certified by one of the various ad hoc committees that sprang into existence following the original 1959 agreement. Since the committees adhered to a rigid definition of Minamata Disease, many victims often needed to wait for decades for official recognition. Not all Minamata cases have manifested the full range of symptoms associated with organic mercury poisonin and the lack of government certification has delayed compensation.
In a case that garnered recent headlines in Japan, Toshiyki Kawakami and his wife Kazue were only officially recognized this year despite their original application 38 years ago. Their application was only processed following medical checkups in May of this year. Recognizing the Kawakamis has raised the official Minamata toll in Kumamoto Prefecture alone to 1,782 but the actual number of cases across Japan is likely much higher (some estimates have placed it higher than 40,000).
And what of Minamato Bay? After decades of reclamation efforts, including reclamation of more than 58 hectares of land, cleanup efforts have produced some positive results. While fish and seafood were declared safe to eat in 1997, levels of mercury concentration have slowly declined and official estimates suggest that background levels have dropped to normal as of 2011. The fight for offical recognition and compensation for many Minamata sufferers is still ongoing with one group of 2,123 Minamata sufferers reaching a settlement with Chisso and various levels of government only last year. Many of the congenital Minamata victims are now in their forties or fifties and often completely dependent on their aging parents for support. Despite active community support programs, the tragedy of Minamata Disease is likely to continue for decades more.